Image forming devices are utilized in an ever-increasing number of applications. An exemplary image forming device is an electro-photographic printer which may be utilized to form hard images. Initially, monochrome electro-photographic printers were introduced, and more recently, electro-photographic printers capable of color imaging have been utilized to provide enhanced imaging operations and capabilities.
Some electro-photographic printer configurations utilize a transfer assembly which may include a belt for receiving a toned image or carrying media which receives a toned image in the process of forming a hard image. For example, the toned image may be received from a photoconductive drum or from some other intermediate material. The toned image may be subsequently transferred to media, or the media having the toned image removed from the belt, to proceed in the imaging process.
The material of the transfer belt is subjected to wear and accordingly the belts are replaced periodically. In some arrangements, the replacement of the belt necessitates replacement of the transfer assembly. Accordingly, determining an end of life condition of a transfer belt or transfer assembly is desired if such components will not last the life of the product.
A mechanical counter may be utilized to count rotations of a transfer belt (similar to an odometer type of device) and to trip a sensor at a predetermined number of rotations of the belt. Utilization of the mechanical counter has associated disadvantages of additional cost of the counter and sensor, additional complexity, and additional components which may be subject to failure. Additionally, any differences between wear resulting from printing versus spinning up/down operations is not accounted for. Another method of determining the life span of a transfer assembly includes counting pages in a formatter. However, this method does not account for the affect of wear during rotations at the beginning and end of print jobs. For the maximum benefit to a consumer, the end of life of the transfer belt should be determined at a point just before print quality or reliability is compromised. The above-described exemplary methods require a designer to limit a life of the transfer belt to worst case conditions or risk an unexpected failure before end of life.
Accordingly, improved methods and apparatus for determining capacity of transfer components are desired.